Tine for loom stop mechanism



Dec. 22, 1964 R. w. NUGENT 3,162,216

TINE FOR LOOM STOP MECHANISM Filed Feb. 21, 1962 FIG.!

INVENTOR 2407/ MH 7k A/IIGI-I/T ATTORNEY United States Patent ()fiice 3,1 62,2 1 6 Patented Dec. 22, 1 964 This invention relates generally to center weft fork stop motions for looms and, as illustrated herein, relates more particularly to weft fork tines of novel form and universal utility but especially useful in the weaving of compact interlaced yarns.

Many textile weaving looms in commercial use are equipped with a center filling stop motion device comprising a weft fork pivotally and centrally mounted to the front of the lay, over an open well, and the free ends of the weft fork projecting directing toward the reed. As the reciprocating lay moves backwardly, the Weft fork is caused to tilt upward and slide through the lower set of Warp yarns, without attaching to them, and permit filling 'by the shuttle in the area beneath the weft fork and above the lower set of Warp yarns. The weft fork is then allowed to descend and determine the presence of the filling yarn as the lay moves forwardly. If filling yarn is present, it supports the weft fork for the desired time interval, but if the filling yarn is absent the weft fork immediately completes its downward motion in to the well in the lay and actuates a mechanism to stop the loom before the lay reaches the fell of the cloth.

Compact interlaced yarn has handling and running characteristics comparable to conventional twisted yarn, even at zero bundle twist and without size or other adhesive treatment. It is comprised of closely adjacent filaments, staple fibers, or a mixture of the two wherein individual filaments, fibers, or yarn plies have been randomly intermingled along the length of the yarn by frictional constraint between adjacent filaments and groups of filaments, all as more fully described in United States Letters Patent No. 2,985,995 granted May 30, 1961, to W. W. Bunting, In, et al. The weft fork tines, commonly 3 to 5 in number, of the prior art forks are generally made of lightweight straight or curved wire having a pointed or slightly rounded free end and a small cross-sectional area as compared to the length of the wire. Its cross-sectional shape may be circular or thinner horizontally than vertically, when in usual operating position. When using prior art Weft forks with Warp yarns of compact interlaced yarn, occasionally a yarn end fails to slide laterally off of the fork tine as the fork moves in the upward tilting direction through the lower set of warp yarns. This .occurs when the tines initial point of contact with the warp yarn is at a zero-twist point or point of low filament-to-filament cohesion in the Warp yarn. The tine pierces the warp yarn, hangs onto en tangled filaments, and raises the warp yarn above'the filling yarns line of insertion or path of shuttle movement instead of permitting the warp yarn to remain under the fill yarn. This results in Weaving the particular warp yarn out of phase causing an desirable misweave, or float, in the cloth. Such pinhead floats, or defects, stand out as bright lumps in the finished fabric.

It is an objective of this invention to provide a form of tine that will quickly allow the lower sets of warp yarns of compact interlaced yarn, to slide laterally off of the tine as it passes through, thus preventing undesirable floats.

Another object of this invention is to provide this novel tine in such form that it will also be more useful with all 'othertypes of textile yarns as compared to the prior art weft fork tine.

Other objects and advantages will be apparent from the drawings and hereinafter.

The objects of this invention are accomplished by providing a novel shape of tine wherein a portion of each weft fork tine intermediate the tine ends precedes the elevated free tip of the tine through the lower set of warp yarns.

In order that the invention may be clearly understood, reference is made to the accompanying drawing which illustrates by way of example preferred embodiments of the invention and in which:

FIGURE 1 is a side elevation of a portion of a loom showing a tine of the preferred embodiment of this invention at a point of initial contact with a running warp yarn.

FIGURE 2 is a vertical sectional view of a tine taken on line A-A of FIGURE 1.

FIGURE 3 is a bottom plan view of the tine shown in FIGURE 1.

FIGURE 4 is a diagrammatic representation of an end view showing a filling yarn passing over 6 warp yarns and under the elevated free tip of the tine of this invention.

FIGURE 5 is a diagrammatic representation of an end view showing a filling yarn passing over 5 warp yarns, and under 1 warp yarn and prior art tine wherein the elevated free end of the tine has pierced the warp yarn and raised it out of phase.

FIGURE 6 is a side elevation of an alternate shape of the tine shown in FIGURE 1.

FIGURE 7 is a side elevation of another alternate shape of the time shown in FIGURE 1.

Referring now to the drawing in which like characters of reference designate similar parts in the various views and representations, 1 designates a warp yarn, moving from lower left to upper right in FIGURE 1, passing over a weft fork tine 2 in the shed area of a loom. The tine 2 is pivotally mounted by suitable means to the lay of the loom (not shown) at end 3; and it is, in point of time, about to move its free lobal portion 8 through the spacing between the warp yarns 1 to take a position above the warp. When the tines 2 are in their upper position; the filling yarn 6 is, as shown in FIGURES 4 and 5, carried by a shuttle (not shown) above the warp yarns 1 and beneath the elevated free ends of the time 2. If the shuttle does not place a piece of filling yarn 6 under the tines 2or, if the filling yarn 6, which the shuttle does lay under the tines 2 is broken-the tines 2 will drop into a well in the lay and actuate the center stop mechanism to stop the loom before the lay reaches the fell of the cloth. If an unbroken filling yarn 6 is properly placed, the sensing, or trailing, edge 10 of the tine will rest on top of the filling yarn 6 and gradually slide forwardly off of the filling yarn 6 as the lay reciprocates to its forward position.

When compact interlaced yarns which have portions or points with zero twist, such as those disclosed in US. Patent 2,985,995 constitute the warp; it has been found that prior art tines, when making initial contact With a warp yarn at a point of zero-twist, or low twist,v are apt to pierce, catch, and become attached to the warp yarn so as to raise it above the subsequent position of the fill yarn. In contrast, contact with a warp yarn by a tine of this invention may initially result in a limited piercing by the elevated free end of the tine at an approximate increased contact area and pressure, with respect to'first contact area 4, along the, engaged length of the'warp i-ted yarn contact area 4 and increased yarn contact area 7 constitute a major'portion of the leading edge of the tine 2' of the fork. These contact areas or portions are positioned as shown along the tine member and have a predetermined ratio of contact area.

The improved weft fork tine -1S preferably stamped 7' from sheet metal in the shapeshown in FIGURE 1 and 1 yarn beyond the area of zero-twist to'jcause the engaged warp yarn to laterally slide off of the tine and resumeits normal position in the lower set of warp yarns. Lim- I mentiwith the'lower warp, and said second portion subsequently also engages the lower warp yarnsduring such movement to insure by its significantly increased cont-act area along the time member length that any lower warp yarn directly engaged by the tine 'member in its movement into engagement with the lower warp will slipilaterally off of said leading edge and return to its position in the plane of they lower warp before being displaced out of 1 said plane more than said givenrnaximum distance due pressed letter P, or it may be a shorter straight line portionwith curved end sections of larger radii.

portion 9 of thetine should have a smooth surface, either j straight or slightly concave, and acting as the fill yarn sensing edge 10, so that the tine vn'll'easily slide forward and off of the filling yarnafter performing its detection function. a

This novel weft fork tineis, as aforestated,especially. 3f useful in the weaving of compact interlaced warp yarns, 1

but it also may be used to advantage. with various types of bulked or textured warp yarns having zero or very low twist and it is believed to be more useful with any textile yarns than is the prior art tine.

'.In accordance with the patent statutes, a detailed dei:

scription of the preferred embodiments of this invention have been set forth.

The stem; v H I i parallel aligned yarns at a given positionalong' a warp, I said movement occurringin-a plane substantially parallel It will be obvious that modifications and other embodimentsmay be made by those skilled in the art without departing from the spirit of the invention" or the scope of the following claims.

I claim; g g i 1. An improved tine for a floom stop mechanism, said tine comprising-a thin elongated member of substantially uniform thickness, said time member further comprising one end adapted to be operatively'rnounted in a loom stop 7 mechanism and the other end positionedandadapted for movement through a warp formed of a plurality of parto the great difference between the high displacing force exerted on the yarn by the increased contact'area of said second portion of the tine leading edge and the low fl'lC- tional force resisting lateral "movement of the engaged yarn off of theleading edge of the thin tine member.

2. An improved tine for a center fill loom stop mechanism for use with interlaced yarns'having portions of Zero twis t,said tine comprising a thin elongated member of substantially uniform thickness and varying width, said tine member further comprising one end adapted to be operatively pivotally mounted ina loom stop mecha- Lnism and the other end positioned and adapted foripivotal movement through aiwarp formed' ofa plurality of to the individual warpyarns and substantially perpendicular to the plane oflthe warp at the given position,

, said tine member further comprising a leading edge constructed and arranged'to move into engagement with; and between the lower warp'yarns without displacing any engaged lower warp yarn more than a given maximum distance out of the plane of thelower warp, and a trailing edge, said'leading edge comprising a first lower warp yarn engaging, portion having a limited yarn contact area inter- Y mediate theendsof the tine member, and a second lower warp yarn engaging portion positioned between said first portion and said other end of said tine member, said second po'rtion having a-significantly increased yarn contact area along the tine member length relative to the 'yarn contact. area of said first 'yarn'engaging portion,

said first and second portions having 'a' predetermined ratio'of contact areas and positioned-along the tinememj ber leadingedge so that said first -.portion engages the yarns of thelower warpfir'st as saidltineinemberamoves into engagement with the lower warp, and said second portion subsequently also engages the lower warp yarns during such Vmovement to insure by its significantly'inallelaligned yarns at a given positionalong-a Warp, i said movement occurring in .a plane substantially parallel to the individual warp yarns and substantially perpensaid tine member further comp'risinga' leading edge con-ff structed. and arranged to move into engagement withgan d 7 between lower warp yarns without displacing any engaged lower warp yarn more than a given mairirnumdistance out of the plane of the lowerwarp, aitrailing'edge,

said leading edge comprising a firstlo wer warp yarn p 1 of the engaged lower warp yarn ofi of theleadin'gedge of engaging portion having a limited yarn contact area inter-:

, mediate the ends of the tine membeniand a second lower warp yarn engaging portionpositioned between said first portion and said other end of said tine member, "saidse end portion having a significantly increased yarncontact areaalong the tine member length relative to/the yarn contact area of said first yarn engaging portion, said first V p and second portions having a predetermined ratio of contact areas and positioned along the tine membenleadingedge so that said firstportion engages the loweri'yarns 7 of the warp first as said tine member moves into enga'g'e-r creased contact area along the tine m'emberi length that any lower warp yarn directly engaged-by the time member in its movement into engagement with the lower, warn r v i r50 r dicular to the planeofithe warp at the given position,

will slip laterally otf of said leading edge and. return to its position inrthe' plane of therlower warp befrnev being displaced out of s'aidplane' more than'said given maxiimurn distance due to the great difference betweenthe high displacing force exerted on the yarn by the increased'com tact area of said second portion ofthe tine leadingedge and the low frictional force resisting" lateral lmovement the thin tine member, V V v References Cited in the file of this patent 7 VUNITED',STAIESYPATENTS j j I; FOREIGN PATENTS j J 3210,8387 Austria Aug. 25, 1960 396,334 Germany I May 30, 1924 Germany Now-9,1936

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION December 22, 1964 Patent No. 3,162,216

Ralph Walter Nugent ars in the above numbered patrtified that error appe Letters Patent should read as It is hereby ce tion and that the said ent requiring oorrec corrected below Column 1 line 28 for "in to" read into line undesirable column 2, line line 1, before 60, for "desirable" read 44, for "tine" read tines "first" insert the column 4 "the" Signed and sealed this column 5,

line 29, strike out 1st day of June 1965.

(SEAL) Attest:

ERNEST w. SWIDER EDWARD J. BRENNER Commissioner of Patents Attesting Officer 

1. AN IMPROVED TINE FOR A LOOM STOP MECHANISM, SAID TINE COMPRISING A THIN ELONGATED MEMBER OF SUBSTANTIALLY UNIFORM THICKNESS, SAID TINE MEMBER FURTHER COMPRISING ONE END ADAPTED TO BE OPERATIVELY MOUNTED IN A LOOM STOP MECHANISM AND THE OTHER END POSITIONED AND ADAPTED FOR MOVEMENT THROUGH A WARP FORMED OF A PLURALITY OF PARALLEL ALIGNED YARNS AT A GIVEN POSITION ALONG A WARP, SAID MOVEMENT OCCURING IN A PLANE SUBSTANTIALLY PARALLEL TO THE INDIVIDUAL WARP YARNS AND SUBSTANTIALLY PERPENDICULAR TO THE PLANE OF THE WARP AT THE GIVEN POSITION, SAID TINE MEMBER FURTHER COMPRISING A LEADING EDGE CONSTRUCTED AND ARRANGED TO MOVE INTO ENGAGEMENT WITH AND BETWEEN LOWER WARP YARNS WITHOUT DISPLACING ANY ENGAGED LOWER WARP YARN MORE THAN A GIVEN MAXIMUM DISTANCE OUT OF THE PLANE OF THE LOWER WARP, AND A TRAILING EDGE, SAID LEADING EDGE COMPRISING A FIRST LOWER WARP YARN ENGAGING PORTION HAVING A LIMITED YARN CONTACT AREA INTERMEDIATE THE ENDS OF THE TINE MEMBER, AND A SECOND LOWER WARP YARN ENGAGING PORTION POSITIONED BETWEEN SAID FIRST PORTION AND SAID OTHER END OF SAID TINE MEMBER, SAID SECOND PORTION HAVING A SIGNIFICANTLY INCREASED YARN CONTACT AREA ALONG THE TINE MEMBER LENGTH RELATIVE TO THE YARN CONTACT AREA OF SAID FIRST YARN ENGAGING PORTION, SAID FIRST AND SECOND PORTIONS HAVING A PREDETERMINED RATIO OF CONTACT AREAS AND POSITIONED ALONG THE TINE MEMBER LEADING EDGE SO THAT SAID FIRST PORTION ENGAGES THE LOWER YARNS OF THE WARP FIRST AS SAID TINE MEMBER MOVES INTO ENGAGEMENT WITH THE LOWER WARP, AND SAID SECOND PORTION SUBSEQUENTLY ALSO ENGAGES THE LOWER WARP YARNS DURING SUCH MOVEMENT TO INSURE BY ITS SIGNIFICANTLY INCREASED CONTACT AREA ALONG THE TINE MEMBER LENGTH THAT ANY LOWER WARP YARN DIRECTLY ENGAGED BY THE TINE MEMBER IN ITS MOVEMENT INTO ENGAGMENT WITH THE LOWER WARP WILL SLIP LATERALLY OFF OF SAID LEADING EDGE AND RETURN TO ITS POSITION IN THE PLANE OF THE LOWER WARP BEFORE BEING GIVEN DISPLACED OUT OF SAID PLANE MORE THAN SAID GIVEN MAXIMUM DISTANCE DUE TO THE GREAT DIFFERENCE BETWEEN THE HIGH DISPLACING FORCE EXERTED ON THE YARN BY THE INCREASED CONTACT AREA OF SAID SECOND PORTION OF THE TINE LEADING EDGE AND THE LOW FRICTIONAL FORCE RESISTING LATERAL MOVEMENT OF THE ENGAGED YARN OFF OF THE LEADING EDGE OF THE THIN TINE MEMBER. 